SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6b28a7cb4dc4f766d7fb280bf4d15a237843867a43bc67f112d94343f59f90' 
  AND token = 'IPZDXZME3rHwwp2CKGH0oGQUCRMRwquusVM2+adxeBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}